Radial vibration dampers are used to reduce radial vibrations in rotating shaft systems. radial vibration dampers can be mounted internally or externally relative to the shaft. The most desirable radial vibration damper for inside a hollow shaft is one that has its first mode shape being radial in nature while being sufficiently decoupled from latter modes. The device must also be easy to insert into the shaft at a designated axial location, and hold its position throughout its operating life. Such a radial vibration damper is typically expensive because the construction is complex and it is unrealistic to invest in expensive injection molds for smaller production runs.
An additional problem encountered while assembling these devices is that the inner diameter of the hollow shaft that receives them generally has loose tolerances that do not allow a robust metal-to-metal press-fit.